Memory devices are typically provided as internal, semiconductor, integrated circuit devices in computers or other electronic devices. There are many different types of memory including random-access memory (RAM), read only memory (ROM), dynamic random access memory (DRAM), synchronous dynamic random access memory (SDRAM), and flash memory.
Flash memory devices have developed into a popular source of non-volatile memory for a wide range of electronic applications. Flash memory devices typically use a one-transistor memory cell that allows for high memory densities, high reliability, and low power consumption. Changes in threshold voltage of the memory cells, through programming (which is often referred to as writing) of charge storage structures (e.g., floating gates or charge traps) or other physical phenomena (e.g., phase change or polarization), determine the data value of each cell. Common uses for flash memory include personal computers, tablet computers, digital cameras, digital media players, cellular telephones, solid state drives and removable memory modules, and the uses are growing.
Detecting the leakage current of different circuitry, such as select lines and word lines, of a memory device may be used to detect defects within the memory device. The defects that may be detected include, for example, word line to word line shorting or word line to substrate shorting. The leakage current of the different circuitry of the memory device may be detected using a probe test at the wafer level using leakage current detection circuitry built into each die of the wafer. The leakage current detection circuitry should use a minimum of die area and accurately detect leakage currents.
For the reasons stated above, and for other reasons stated below which will become apparent to those skilled in the art upon reading and understanding the present specification, there is a need in the art for alternative methods for leakage current detection, and system and apparatus to perform such methods.